Indicating device



Se t. 15, 1936.

R. L. WILLIAMS INDICATING DEVICE Original Filed Dec. 13, 1929 a lllllllllllllllllIlllllllllllllHlllll Patented Sept. is, 1536.

- UNITED STATES PATENT 'oFF cE 2,054,109 mnrca'rmc nnvrcn Original application December 13, 1929, Serial No. 413,917. Divided and this application June 16. isaaseriai No. 730,891

Claims. (01- 116-429) This application is a division of my copending application Serial No. 413,917, Pat. No. 2,015,762 iiledDecember 13, 1929.

. The present invention relates to distance and i 5 depth measurement, and more particularly to the system, apparaiais and methods employed in determining depths and heights by transmitting a sound or compressional wave signal and measuring the time interval between the emission of the '10 sound and 'the receipt of the impulse reflected from the object whose distance is to bemeasured.

Various general types of systems and methods have been, employed in measuring depths and distances in the manner above indicated,--some with it more or less commercial success. In one system inparticular howevena rotatable indicator is set in motion when the original sound is transmitted and is stopped by a braking mechanism when the echo retums, the angle through which.

a the indicator has rotated being a measure of the distance. Much diiliculty has been encountered .in eflectively' stopping the rotating membefwith .the necessary precision when theecho returns. A still greater difliculty is that the initial signal has a tendency to act on the braking mec,

thereby preventing'any motion of the disc, and,

of course, preventing a measurement. To avoid this it was found necessary carefully to shield the sound receiver from the direct signal.

The present invention completely eliminates these difliculties.. Q

It has also been found in practice that a sharp sound impulse is well suited to depth sounding.

Such an impulse has been produced by an explo- 5 Mon, or by. an impact striker such as, for exampie, is shown in the copendingapplication of Edwin E. Turner, Jr., Serial No. 270,660. The use 'of an explosivefor'this pin'pose is attended by a number of objections. The impact strikers em- 40 ployed in the prior art have required a comparatlvely large sourceof power for their operation.

The present invention contemplates the use or an impact striker operated by handor foot power, thereby avoiding the disadvantages of the use of an explosive, and also avoiding the necessity for having a large source of'power.

A further obie of the present invention is to produce a depth unding system, method and 7 5o apparatus which will be emcient and accurate in operation, simple and cheap to manufacture.

Additional features of the invention will be disclosed in the description of the drawing. in which Figure 1 shows schematically an arrangement 65 of the system employed in the present invention.

through the closed contacts 6 and I p Figure 2 shows in elevation a front view of the scale. shown in Figure 1,

Figure 3 shows a. modification of the system shown in Figure l, and

Figure 4 shows in section the apparatus illus- 5 trated in Figure 3.

In Figure l, l illustrates a manually operated impact striker which strikes against the ship's, skin 2, sending out a sharp sound signal into the water.

The vibrations of the ships skin caused by the blow of the striker l actuate the diaphragm 3 of the hydrophonic relay 4, thereby causing the pivoted arm 5 to move upwards, separating the con- .tacts 6 and lwhich are in series with the switch 8, l5 'electromagnet coil 9 and battery Ill. The hydrophonic relay schematically shown in the drawing 1 is similar to the apparatus described in my United States Patent No. 1,725,038 granted to me Augu t 20, 1929. 1

When the switch 8 is closed, the electromagnet 9 is energized by current, from the battery I0 roducing a Upon the magnetic pull on spring armature l l.

opening of contacts 5 and I, the armature isreleased,'thereby"setting the inertia disc l2 in rotation. The disc can rotate until the arm l3 strikes stop It.

To the axis of the disc is attached a coil spring l5 whose other end is fastened to an arm I6 mounted on the stop It. When the disc rotates by virtue of the energy imparted to it by armature l I, it winds up the spring so that after arm l3 strikes stop I4 the spring returns the disc to its original position. Also mounted upon theqdisc and rotatable with it is mirror l'l whose function will be described below.

The sound impulse sent into the water by the striker I travels to the bottom and after reflection is received by the hydrophone l8 which may 40 be mounted in a tank l9 filled with water. The

hydrophone is energized by current from potentiometer 20 and battery 2|. A switch 22 is provided to control the hydrophone current.

The sound impulse received by the hydrophone is translated into a corresponding electric im ulse which is passed through transformer 23 and to the grid of detector tube 24, thereby producing a negative charge on the grid of tube 25 which cuts off the plate current flowing in the plate circuit of tube 25 through the primary of step-up transformer- 26 and consequently induces a high potential in the secondary of the transformer causing a discharge of the indicator 21. Plate current is supplied to tube 25 when the switch 29 is closed. ,55

The latter may be any form of indicator which will produce a luminous'indication at the time of 7 receipt of the echo, although it is preferred to use an electricdischarge tube filled with gas such as neon;

After a negative charge has been placed on the flowing through the primary of transformer 26 is thus rapidly built up again, although not so rapidly as it is broken down when the echo is received. The time constant of'the grid circuit of tube 25 is determined by the values of resistance 3| and condenser 30. This circuit is described in more detail in the United States Patent No. 1,775,073 granted to Edwin E. Turner, Jr.; September 2, 1930.

During the time whilethe sound impulse has been traveling to the sea bottom and returning to the hydrophone, the inertia disc i2 carrying the mirror I! has rotated through anangle determined by the depth being measured, the starting force applied by the armature Ii and the retarding force of the spring I5 being regarded as constants. The light emitted by the discharge of the-indicator when the echo is received passes through the lens 32 and is reflected from the mirror H to a translucent scale 28 which i may be graduated directly-in terms of depth and ,Likewise, the reflection of the luminous indicator at the moment of the receipt of the echo will, if

the scale is properly calibrated, fall upon the scale at .a point indicating the depth measured.

Instead of determining the instantaneous position of the mirror when the echo is received \by causing the mirror to reflect the light beam on a scale, the mirror may be arranged to reflect the light from the neon tube discharge directly to the eye of the'observer who will note stroboscopically the instantaneous position of the mirror with respect to a scale when the discharge occurs. This modification of the invention is illustrated in [Figures 3. .and 4,'the latter being a section along the line AB in Figure 3.

In thisapparatus, the same type of signal-send. ing and receiving apparatus may be employed as shown in -Figure 1. Likewise, an inertia disc I! isprovided which is set in motion' by the spring armature II when the signal is emitted and i0- :tates against the action of the return'spring l5 until the arm l3 strikes stop l4.

Mounted on the disc I! and rotatable with it is an index 33 which travels in front of a scale 35. The latter may be translucent and illuminated from the rear bya-source of light 39 to a sumcient brightness to enable an observer to read: the graduations thereon.

Just above and in front of the scale is provided an electric discharge tube 36, which maybe filled with a gas such as neon, and whose electrodes 31 and 38 are supplied with a discharge potential similarly as in Figure 1.

from transformer 26 when the echo is received, The tube 36, however, is arcuate in shape and extends over the entire length of the scale. When the discharge occurs the light produced is reflected directly to the eye of the observer by a mirror mounted on the bent portion 34 of the index 33. Alternatively the bent portion 34 may be silvered or otherwise adapted to reflect light. The momentary position of the latter will thus appear to the observer as a bright spot of red light, if a neon tube is used, against the scale.

If the direct light from the discharge tube 36 be prevented from reaching the eye of the observer by a shield 40, shown in Figure 4, the index will be substantially invisible except when illuminated-by the discharge, thereby producing a remarkably effective indication. 1

While the system has been described as employing a hand-, or foot-operated striker to send the initial signal, in order to simplify and to reduce the cost of the apparatus, it is, of course, evident that the indicating and time measuring apparatus described above will operate equally well with any otherform of impact striker; e. g., that shown im 2 departing from the spirit and scope of the invention as set forth in the claims.

What is claimed is:

1. In an indicating device, a member provided with an arcuate scale, a pointer, a pivotal mounting for the pointer, the pointer having a free end portion bent backwards towards the scale and provided with a reflecting surface and an intermittently operated source of light arranged to illuminate the reflecting surface in 19.11 positions of the pointer, said member and said pointer being so arranged asto present the reflecting surface as an illuminated tions of the scale.

2. In an indicating device, a member provided with a scale, a pointer, means for mounting the pointer to move over said scale, said pointer having a free end portion bent backwards towards the scale and providing a reflecting surface and, an intermittently operated source of light arranged to illuminate the reflecting surface in" all positions of the pointer, said member and said pointer being so arranged as to present-the reflecting surface as an illuminated spot against the graduations of the scale.

3. In an indicating device provided with a scale, a pointer, 'means for moving the pointer over the scale, the pointer having a free end portion bent towards the scale and providing a reflecting surface and an intermittently operated source of light substantially extending the length of said scale and arranged to illuminate the reflecting surface in all positions of the pointer, ,the reflecting surface of said pointer being arranged with reference to the scale to make the spot of light. appear against thegraduations of the scale. V

4. In an indicating device,- a member provided with an arcuate scale, a pointer, "a pivotal mounting for the pointer, the pointer having a spot against the graduafree end portion bent towards the scale and pro- 1 vided with a reflecting surface and an arcuate neonlight adapted to be operated intermittently to illuminate the reflecting surface in all positions of the pointer, the reflecting surface. cream ,1

5. In an indicating device, a member provided with an arcuate scale, the said member-being translucent and means providing a light source to illuminate said scale from the rear, a pointer and means mounting the pointer before the scale, said pointer having a portion inclined towards the scale and provided with a reflecting surface and an intermittently operated source of light arranged to illuminate the reflecting surface in all positions of the pointer, the reflecting surface of said pointer being arranged with reference to the scale to make the spot of light appear against the graduations of the scale.

ROBERT LONGFELLOW WILLIAMS. 

